The present invention relates generally to a method for the preparation and packing of food products. More specifically, the present invention relates to the preparation and packaging of a product based on fish, which through sterilization has been given an extended keeping quality. The product is disintegrated and heated in a known manner to such an extent that the product becomes sterile.
It is known in foodstuff technology that food products can be treated through sterilization so that they acquire an extended keeping quality. For the most part this sterilization takes place by means of heat in such a manner that the product is heated to a temperature generally exceeding 140.degree. C. for a time which may vary between a few seconds and some minutes, depending on the product which is to be sterilized. Usually such a sterilization takes place after the food product has been packed in hermetically closed containers, e.g. tins, the sterilization taking place in a so-called autoclave, wherein the closed tins are heated during a time which is long enough for the contents of the tins as well as the insides of the tins to become sterile. It is known that such sterilized tins have a very long keeping quality, but it is an inconvenience that the autoclaving principle is so time-consuming and costly. Moreoever, due to the required long-time heating the product often acquires a disagreeable flavor because of the protein substances of the product are denatured during the long-time heating.
It is also known that products can be sterilized separately and then packed into previously sterilized packages. This is done e.g. in the packaging of so-called aseptic milk, where the milk is briefly heated to approx. 140.degree. C. during a few seconds. Subsequently, the milk is introduced, under aseptic conditions, into previously sterilized packing containers or enclosed in previously sterilized packing material in such a manner, that the finished package on the one hand has a sterile inside and on the other hand sterile contents. Thus, the packed milk is given a keeping quality which can extend over several months.
It has not been possible heretofore to apply this separate sterilization of food products for subsequent packing in presterilized packing containers to those types of contents which have a certain dimensional stability, that is to say coagulated products of the type of aspic, sausage-meat or fish products of the quenelle type or other pie-like fish product. The problem in such a package consists in producing the sterilized product in a form which corresponds to the inner space in a previously sterilized packing container, and subsequently combining the formed product with the packing container. Finally, closing the packing container under aseptic conditions to obtain a package with sterile interior, wherein the sterilized product retains its sterility is also a problem. A method and an arrangement for solving this problem is given in the following description of the present invention wherein the product in connection with or after the sterilizing heating is divided into portions which are each given an outer shape and size which correspond to or are slightly less than the space in the packing container intended for the product. The packing container is treated in such a manner that its insides become sterile, and the product, divided into portions and sterilized, is introduced into the sterilized packing containers, which are closed under aseptic conditions to form individual packages containing sterile product.